CSHARP-1283: fixing issue where a short period of connectivity occurs and then shuts down when the replica set configuration has a different host than what was provided by the seedlist.

Author: craiggwilson

src/MongoDB.Driver.Core.Tests/Core/Clusters/MultiServerClusterTests.cs

@@ -146,6 +146,25 @@ public void Should_remove_a_server_that_is_no_longer_in_the_primary_host_list()
             description.Servers.Should().BeEquivalentTo(GetDescriptions(_firstEndPoint, _secondEndPoint));
         }
 
+        [Test]
+        public void Should_remove_a_server_whose_canonical_end_point_does_not_match_its_provided_end_point()
+        {
+            var nonCanonicalEndPoint = new DnsEndPoint("wrong", 27017);
+            _settings = _settings.With(endPoints: new[] { nonCanonicalEndPoint, _secondEndPoint });
+
+            var subject = CreateSubject();
+            subject.Initialize();
+
+            PublishDescription(nonCanonicalEndPoint, ServerType.ReplicaSetPrimary,
+                hosts: new[] { _firstEndPoint, _secondEndPoint },
+                canonicalEndPoint: _firstEndPoint);
+
+            var description = subject.Description;
+            description.State.Should().Be(ClusterState.Disconnected);
+            description.Type.Should().Be(ClusterType.ReplicaSet);
+            description.Servers.Should().BeEquivalentTo(GetDescriptions(_firstEndPoint, _secondEndPoint));
+        }
+
         [Test]
         public void Should_not_remove_a_server_that_is_no_longer_in_a_secondaries_host_list()
         {
@@ -449,7 +468,7 @@ private void PublishDisconnectedDescription(EndPoint endPoint)
             _serverFactory.PublishDescription(description);
         }
 
-        private void PublishDescription(EndPoint endPoint, ServerType serverType, IEnumerable<EndPoint> hosts = null, string setName = null, EndPoint primary = null, ElectionId electionId = null)
+        private void PublishDescription(EndPoint endPoint, ServerType serverType, IEnumerable<EndPoint> hosts = null, string setName = null, EndPoint primary = null, ElectionId electionId = null, EndPoint canonicalEndPoint = null)
         {
             var current = _serverFactory.GetServerDescription(endPoint);
 
@@ -462,6 +481,7 @@ private void PublishDescription(EndPoint endPoint, ServerType serverType, IEnume
             var description = current.With(
                 averageRoundTripTime: TimeSpan.FromMilliseconds(10),
                 replicaSetConfig: serverType.IsReplicaSetMember() ? config : null,
+                canonicalEndPoint: canonicalEndPoint,
                 electionId: electionId,
                 state: ServerState.Connected,
                 tags: null,

src/MongoDB.Driver.Core.Tests/Core/Connections/IsMasterResultTests.cs

@@ -20,6 +20,7 @@
 using MongoDB.Bson;
 using MongoDB.Driver.Core.Clusters;
 using MongoDB.Driver.Core.Connections;
+using MongoDB.Driver.Core.Misc;
 using MongoDB.Driver.Core.Servers;
 using NUnit.Framework;
 
@@ -130,6 +131,18 @@ public void MinWireVersion_should_parse_document_correctly(string json, int expe
             subject.MinWireVersion.Should().Be(expected);
         }
 
+        [Test]
+        [TestCase("{ }", null)]
+        [TestCase("{ me: 'localhost:27018' }", "localhost:27018")]
+        public void Me_should_parse_document_correctly(string json, string expectedEndPoint)
+        {
+            var endPoint = expectedEndPoint == null ? (EndPoint)null : EndPointHelper.Parse(expectedEndPoint);
+
+            var subject = new IsMasterResult(BsonDocument.Parse(json));
+
+            subject.Me.Should().Be(endPoint);
+        }
+
         [Test]
         [TestCase("{ ok: 1, isreplicaset: true, setName: \"awesome\", ismaster: true }", ServerType.ReplicaSetGhost)]
         [TestCase("{ ok: 1, setName: \"awesome\", ismaster: true }", ServerType.ReplicaSetPrimary)]

src/MongoDB.Driver.Core.Tests/Core/Servers/ServerDescriptionTests.cs

@@ -48,6 +48,7 @@ public void Constructor_with_serverId_and_endPoint_only_should_return_disconnect
         {
             var subject = new ServerDescription(__serverId, __endPoint);
             subject.AverageRoundTripTime.Should().Be(TimeSpan.Zero);
+            subject.CanonicalEndPoint.Should().BeNull();
             subject.ElectionId.Should().BeNull();
             subject.EndPoint.Should().Be(__endPoint);
             subject.ReplicaSetConfig.Should().BeNull();
@@ -63,6 +64,7 @@ public void Constructor_with_serverId_and_endPoint_only_should_return_disconnect
         public void Constructor_with_multiple_parameters_should_return_properly_initialized_instance()
         {
             var averageRoundTripTime = TimeSpan.FromSeconds(1);
+            var canonicalEndPoint = new DnsEndPoint("localhost", 27017);
             var electionId = new ElectionId(ObjectId.GenerateNewId());
             var replicaSetConfig = new ReplicaSetConfig(
                 new[] { new DnsEndPoint("localhost", 27017), new DnsEndPoint("localhost", 27018) },
@@ -81,13 +83,15 @@ public void Constructor_with_multiple_parameters_should_return_properly_initiali
                 state: state,
                 type: type,
                 averageRoundTripTime: averageRoundTripTime,
+                canonicalEndPoint: canonicalEndPoint,
                 electionId: electionId,
                 replicaSetConfig: replicaSetConfig,
                 tags: tags,
                 version: version,
                 wireVersionRange: wireVersionRange);
 
             subject.AverageRoundTripTime.Should().Be(TimeSpan.FromSeconds(1));
+            subject.CanonicalEndPoint.Should().Be(canonicalEndPoint);
             subject.ElectionId.Should().Be(electionId);
             subject.EndPoint.Should().Be(__endPoint);
             subject.ReplicaSetConfig.Should().Be(replicaSetConfig);
@@ -98,6 +102,7 @@ public void Constructor_with_multiple_parameters_should_return_properly_initiali
         }
 
         [TestCase("AverageRoundTripTime")]
+        [TestCase("CanonicalEndPoint")]
         [TestCase("ElectionId")]
         [TestCase("EndPoint")]
         [TestCase("ReplicaSetConfig")]
@@ -110,6 +115,7 @@ public void Constructor_with_multiple_parameters_should_return_properly_initiali
         public void Equals_should_return_false_when_any_field_is_not_equal(string notEqualField)
         {
             var averageRoundTripTime = TimeSpan.FromSeconds(1);
+            var canonicalEndPoint = new DnsEndPoint("localhost", 27017);
             var electionId = new ElectionId(ObjectId.GenerateNewId());
             var endPoint = new DnsEndPoint("localhost", 27017);
             var replicaSetConfig = new ReplicaSetConfig(
@@ -130,6 +136,7 @@ public void Equals_should_return_false_when_any_field_is_not_equal(string notEqu
                 state: state,
                 type: type,
                 averageRoundTripTime: averageRoundTripTime,
+                canonicalEndPoint: canonicalEndPoint,
                 replicaSetConfig: replicaSetConfig,
                 tags: tags,
                 version: version,
@@ -138,6 +145,7 @@ public void Equals_should_return_false_when_any_field_is_not_equal(string notEqu
             switch (notEqualField)
             {
                 case "AverageRoundTripTime": averageRoundTripTime = averageRoundTripTime.Add(TimeSpan.FromSeconds(1)); break;
+                case "CanonicalEndPoint": canonicalEndPoint = new DnsEndPoint("localhost", 27018); break;
                 case "ElectionId": electionId = new ElectionId(ObjectId.Empty); break;
                 case "EndPoint": endPoint = new DnsEndPoint(endPoint.Host, endPoint.Port + 1); serverId = new ServerId(__clusterId, endPoint); break;
                 case "ReplicaSetConfig": replicaSetConfig = new ReplicaSetConfig(replicaSetConfig.Members, "newname", replicaSetConfig.Primary, replicaSetConfig.Version); break;
@@ -155,6 +163,7 @@ public void Equals_should_return_false_when_any_field_is_not_equal(string notEqu
                 state: state,
                 type: type,
                 averageRoundTripTime: averageRoundTripTime,
+                canonicalEndPoint: canonicalEndPoint,
                 electionId: electionId,
                 replicaSetConfig: replicaSetConfig,
                 tags: tags,
@@ -177,6 +186,7 @@ public void Equals_should_return_true_when_all_fields_are_equal()
         }
 
         [TestCase("AverageRoundTripTime")]
+        [TestCase("CanonicalEndPoint")]
         [TestCase("ElectionId")]
         [TestCase("ReplicaSetConfig")]
         [TestCase("Tags")]
@@ -186,6 +196,7 @@ public void Equals_should_return_true_when_all_fields_are_equal()
         public void WithHeartbeat_should_return_new_instance_when_a_field_is_not_equal(string notEqualField)
         {
             var averageRoundTripTime = TimeSpan.FromSeconds(1);
+            var canonicalEndPoint = new DnsEndPoint("localhost", 27017);
             var electionId = new ElectionId(ObjectId.GenerateNewId());
             var replicaSetConfig = new ReplicaSetConfig(
                 new[] { new DnsEndPoint("localhost", 27017), new DnsEndPoint("localhost", 27018) },
@@ -213,6 +224,7 @@ public void WithHeartbeat_should_return_new_instance_when_a_field_is_not_equal(s
             switch (notEqualField)
             {
                 case "AverageRoundTripTime": averageRoundTripTime = averageRoundTripTime.Add(TimeSpan.FromSeconds(1)); break;
+                case "CanonicalEndPoint": canonicalEndPoint = new DnsEndPoint("localhost", 27018); break;
                 case "ElectionId": electionId = new ElectionId(ObjectId.Empty); break;
                 case "ReplicaSetConfig": replicaSetConfig = new ReplicaSetConfig(replicaSetConfig.Members, "newname", replicaSetConfig.Primary, replicaSetConfig.Version); break;
                 case "Tags": tags = new TagSet(new[] { new Tag("x", "b") }); break;
@@ -223,6 +235,7 @@ public void WithHeartbeat_should_return_new_instance_when_a_field_is_not_equal(s
 
             var serverDescription2 = subject.With(
                 averageRoundTripTime: averageRoundTripTime,
+                canonicalEndPoint: canonicalEndPoint,
                 replicaSetConfig: replicaSetConfig,
                 state: ServerState.Connected,
                 electionId: electionId,

src/MongoDB.Driver.Core.Tests/MongoDB.Driver.Core.Tests.csproj

@@ -285,6 +285,12 @@
     <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\sec_not_auth.yml" />
     <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\unexpected_mongos.yml" />
     <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\wrong_set_name.yml" />
+    <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\primary_mismatched_me.json" />
+    <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\primary_mismatched_me.yml" />
+    <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\primary_to_no_primary_mismatched_me.json" />
+    <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\primary_to_no_primary_mismatched_me.yml" />
+    <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\secondary_mismatched_me.json" />
+    <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\rs\secondary_mismatched_me.yml" />
     <None Include="Specifications\server-discovery-and-monitoring\tests\sharded\multiple_mongoses.yml" />
     <EmbeddedResource Include="Specifications\server-discovery-and-monitoring\tests\sharded\non_mongos_removed.json" />
     <None Include="Specifications\server-discovery-and-monitoring\tests\sharded\non_mongos_removed.yml" />

src/MongoDB.Driver.Core.Tests/Specifications/server-discovery-and-monitoring/TestRunner.cs

@@ -76,6 +76,7 @@ private void ApplyResponse(BsonValue response)
             var description = currentDescription.With(
                 state: isMasterResult.Wrapped.GetValue("ok", false).ToBoolean() ? ServerState.Connected : ServerState.Disconnected,
                 type: isMasterResult.ServerType,
+                canonicalEndPoint: isMasterResult.Me,
                 electionId: isMasterResult.ElectionId,
                 replicaSetConfig: isMasterResult.GetReplicaSetConfig());
 

src/MongoDB.Driver.Core/Core/Clusters/MultiServerCluster.cs

@@ -281,6 +281,12 @@ private ClusterDescription ProcessReplicaSetChange(ClusterDescription clusterDes
             clusterDescription = clusterDescription.WithServerDescription(args.NewServerDescription);
             clusterDescription = EnsureServers(clusterDescription, args.NewServerDescription);
 
+            if (args.NewServerDescription.CanonicalEndPoint != null &&
+                !EndPointHelper.Equals(args.NewServerDescription.CanonicalEndPoint, args.NewServerDescription.EndPoint))
+            {
+                return RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, "CanonicalEndPoint is different than seed list EndPoint.");
+            }
+
             if (args.NewServerDescription.Type == ServerType.ReplicaSetPrimary)
             {
                 if (args.NewServerDescription.ElectionId != null)

src/MongoDB.Driver.Core/Core/Connections/IsMasterResult.cs

@@ -145,6 +145,23 @@ public int MaxMessageSize
             }
         }
 
+        /// <summary>
+        /// Gets the endpoint the server is claiming it is known as.
+        /// </summary>
+        public EndPoint Me
+        {
+            get
+            {
+                BsonValue value;
+                if (_wrapped.TryGetValue("me", out value))
+                {
+                    return EndPointHelper.Parse((string)value);
+                }
+
+                return null;
+            }
+        }
+
         /// <summary>
         /// Gets the type of the server.
         /// </summary>

src/MongoDB.Driver.Core/Core/Servers/ClusterableServer.cs

@@ -272,6 +272,7 @@ private async Task<bool> HeartbeatAsync(CancellationToken cancellationToken)
 
                 newDescription = _baseDescription.With(
                     averageRoundTripTime: averageRoundTripTimeRounded,
+                    canonicalEndPoint: isMasterResult.Me,
                     electionId: isMasterResult.ElectionId,
                     maxBatchCount: isMasterResult.MaxBatchCount,
                     maxDocumentSize: isMasterResult.MaxDocumentSize,

src/MongoDB.Driver.Core/Core/Servers/ServerDescription.cs

@@ -35,6 +35,7 @@ public sealed class ServerDescription : IEquatable<ServerDescription>
     {
         // fields
         private readonly TimeSpan _averageRoundTripTime;
+        private readonly EndPoint _canonicalEndPoint;
         private readonly ElectionId _electionId;
         private readonly EndPoint _endPoint;
         private readonly Exception _heartbeatException;
@@ -57,6 +58,7 @@ public sealed class ServerDescription : IEquatable<ServerDescription>
         /// <param name="serverId">The server identifier.</param>
         /// <param name="endPoint">The end point.</param>
         /// <param name="averageRoundTripTime">The average round trip time.</param>
+        /// <param name="canonicalEndPoint">The canonical end point.</param>
         /// <param name="electionId">The election identifier.</param>
         /// <param name="heartbeatException">The heartbeat exception.</param>
         /// <param name="maxBatchCount">The maximum batch count.</param>
@@ -74,6 +76,7 @@ public ServerDescription(
             ServerId serverId,
             EndPoint endPoint,
             Optional<TimeSpan> averageRoundTripTime = default(Optional<TimeSpan>),
+            Optional<EndPoint> canonicalEndPoint = default(Optional<EndPoint>),
             Optional<ElectionId> electionId = default(Optional<ElectionId>),
             Optional<Exception> heartbeatException = default(Optional<Exception>),
             Optional<int> maxBatchCount = default(Optional<int>),
@@ -95,6 +98,7 @@ public ServerDescription(
             }
 
             _averageRoundTripTime = averageRoundTripTime.WithDefault(TimeSpan.Zero);
+            _canonicalEndPoint = canonicalEndPoint.WithDefault(null);
             _electionId = electionId.WithDefault(null);
             _endPoint = endPoint;
             _heartbeatException = heartbeatException.WithDefault(null);
@@ -123,6 +127,16 @@ public TimeSpan AverageRoundTripTime
             get { return _averageRoundTripTime; }
         }
 
+        /// <summary>
+        /// Gets the canonical end point. This is the endpoint that the cluster knows this 
+        /// server by. Currently, it only applies to a replica set config and will match
+        /// what is in the replica set configuration.
+        /// </summary>
+        public EndPoint CanonicalEndPoint
+        {
+            get { return _canonicalEndPoint; }
+        }
+
         /// <summary>
         /// Gets the election identifier.
         /// </summary>
@@ -291,6 +305,7 @@ public bool Equals(ServerDescription other)
 
             return
                 _averageRoundTripTime == other._averageRoundTripTime &&
+                object.Equals(_canonicalEndPoint, other._canonicalEndPoint) &&
                 object.Equals(_electionId, other._electionId) &&
                 EndPointHelper.Equals(_endPoint, other._endPoint) &&
                 object.Equals(_heartbeatException, other._heartbeatException) &&
@@ -313,6 +328,7 @@ public override int GetHashCode()
             // revision is ignored
             return new Hasher()
                 .Hash(_averageRoundTripTime)
+                .Hash(_canonicalEndPoint)
                 .Hash(_electionId)
                 .Hash(_endPoint)
                 .Hash(_heartbeatException)
@@ -351,6 +367,7 @@ public override string ToString()
         /// Returns a new instance of ServerDescription with some values changed.
         /// </summary>
         /// <param name="averageRoundTripTime">The average round trip time.</param>
+        /// <param name="canonicalEndPoint">The canonical end point.</param>
         /// <param name="electionId">The election identifier.</param>
         /// <param name="heartbeatException">The heartbeat exception.</param>
         /// <param name="maxBatchCount">The maximum batch count.</param>
@@ -368,6 +385,7 @@ public override string ToString()
         /// </returns>
         public ServerDescription With(
             Optional<TimeSpan> averageRoundTripTime = default(Optional<TimeSpan>),
+            Optional<EndPoint> canonicalEndPoint = default(Optional<EndPoint>),
             Optional<ElectionId> electionId = default(Optional<ElectionId>),
             Optional<Exception> heartbeatException = default(Optional<Exception>),
             Optional<int> maxBatchCount = default(Optional<int>),
@@ -383,6 +401,7 @@ public ServerDescription With(
         {
             if (
                 averageRoundTripTime.Replaces(_averageRoundTripTime) ||
+                canonicalEndPoint.Replaces(_canonicalEndPoint) ||
                 electionId.Replaces(_electionId) ||
                 heartbeatException.Replaces(_heartbeatException) ||
                 maxBatchCount.Replaces(_maxBatchCount) ||
@@ -400,6 +419,7 @@ public ServerDescription With(
                     _serverId,
                     _endPoint,
                     averageRoundTripTime: averageRoundTripTime.WithDefault(_averageRoundTripTime),
+                    canonicalEndPoint: canonicalEndPoint.WithDefault(_canonicalEndPoint),
                     electionId: electionId.WithDefault(_electionId),
                     heartbeatException: heartbeatException.WithDefault(_heartbeatException),
                     maxBatchCount: maxBatchCount.WithDefault(_maxBatchCount),